Construction sites are prone to erosion of topsoil and loose silt from both wind and rain. Unchecked erosion can cause serious damage to the environment, injure surrounding farm lands, block highways, and choke navigation routes. Certain aquatic environments are especially sensitive to silt intrusion. It is swell known that silt from construction run-off or navigation dredging can kill coral reefs and choke-off other bay invertebrates. Marshlands are similarly sensitive. Protecting natural environments that are near construction areas necessitates erecting barriers to arrest erosion.
Many systems and apparatuses exist to arrest erosion and drifting of loose sand, snow, or silt. U.S. Pat. No. 4,756,511 issued to Wright, III discloses a silt fence comprising a plurality of pointed end stakes having fabric secured to the stakes with mounting strips. U.S. Pat. No. 3,426,536 issued to Danz discloses a device for impeding the flow of sand or silt utilizing an interweaving of horizontal strips of material between spaced apart upright posts. The strips have a feature of vertical relocation. U.S. Pat. No. 4,932,634 issued to Sura shows a snow fence utilizing horizontal plastic slats supported by attachment ears on fence posts. U.S. Pat. No. 5,131,630 issued to Nash discloses a drift fence for retaining snow or sand using tubular slats held together by parallel cords and H-shaped retainers. However, with the exception of Wright, III, these systems provide relatively complicated or expensive solutions to address drifting or eroding sand or silt. Wright, lit, incorporates inexpensive woven fabric mounted to simple wooden stakes with mounting strips to create a barrier, but Wright does not provide a means for anchoring the bottom of the fabric to the ground at an intermediate point between each wooden stake. Without adequate anchoring, silt and other loose topsoil will invariably pass beneath a barrier fence as the silt builds up against the barrier. Shortening the distance between the support stakes to adequately anchor the fence fabric is prohibitively expensive due to material and installation costs. A need exists for an inexpensive device for securing the bottom of fabric fencing to the ground between fence supports at a fraction of the labor costs of erecting a full support.
Wright and the other references also do not provide any means for gauging the burial depth of the lower edge of a fabric barrier. To effectively prevent the erosion of silt or other small particle erosion, a fabric style barrier should have its lower edge buried beneath the ground to a predetermined depth, typically six inches. Some states, in fact, mandate use of silt fences or barriers at construction sites to prevent erosion. Erosion control construction codes that require silt fencing usually specify a minimum burial depth of the lower edge of the fencing fabric. These codes place a heavy burden on construction foreman who must verify code compliance. Most construction managers currently measure fencing depth during installation or after installation through manual inspection probes. However, this method requires additional training for construction managers and work crews, and does not yield consistent depth results. Therefore, there is a need in the industry for a quick and inexpensive system to determine fence burial depth that can be used by construction foreman work crews.
In addition to construction codes, some localities require county inspectors to verify the depth of the silt fencing. The inspectors either must be present during the installation or probe the fence depth manually to verify depth. This places a heavy burden on inspectors who may not have the time to adequately inspect the fencing. A built-in gauge on the lower edge of the fabric fence would greatly simplify an inspectors task and increase quality inspections. Therefore, the construction industry has a need for code certified gauges can provide readily discernible and highly visible indicia so that inspectors and foremen can verify correct depth from a distance.
In addition to burying silt or barrier fencing to prevent erosion cyclone fences are frequently buried to prevent entry of animals either into or out of a protected area. Proper burial depth and the anchoring of the bottom the fences is also important as in the case of the silt fencing. The disclosed invention also addresses this need.